Method of manufacturing sound-records.



No. 808,843. l PATENTED JAN. 2, 1906.

W. H. HOYT & W. J. GAVEN.

METHOD 0F MANUFACTURING SOUND RECORDS.

' APPLICATION FILED DBO. a. 1904. v

Egwdered/ 4 (Blauwe4 WWI-933292351' UNITED sTATEs PATENT FENCE.

WILLIAM HELM HOYT AND WILLIAM JOSEPH GAVEN, OF BRIDGEPORT, CONNECTICUT,ASSIGNORS TO THE BURT COMPANY, OF HACKENSACK, NEW JERSEY, A CORPORATIONOF NEW JERSEY.

Specification of Letters Patent.

Patented Jan. 2, 1906.

Application led December 8, 1904. Serial No. 236,074.

To all whom, t may concern,.-

Be it known that we, WILLIAM HELM HoYT and WILLIAM JOSEPH GAvEN, of

Bridgeport, Connecticut, have invented a new and useful Improvement inMethods of Manufacturing Sound-Records, which invention is fully setforth in the following specification.

The present invention relates to an improvement upon the processdescribed in our application for patent, Serial No. 212,216, filed June11, 1904, which describes the production of pressed sound-records havingthe glaze (shellec, for example,) practically confined to the surfacepart of the record. In carrying out the invention as therein describedwe formed two batches of the plastic material, one containing the usualproportion of shellac, the other containing no (or a very slightquantity of) shellac. The two batches were rolled into sheets, thatcontaining the shellac being about half the thickness of the othersheet. The two sheets were placed one upon the other and united by heatand pressure, which could be applied simultaneously with the impressionof the sound-record upon the surface. In carrying out the process inthat way we found that the surface sheet would not invariably flow so asto cover the tablet continuously, and the result would be an occasionalrecord having soft spots which would quickly wear away. Furthermore, itwas not easy to use always the same amount of the surface stock, thusincurring either the risk lof using too little or the waste of usingmore than necessary. By the present invention we remedy thesedifficulties completely. Instead of applying the stock to form the faceof the tablet in a plastic condition we apply it in a dry state in theform of a powder, whereby a continuous layer of practically uniformthickness can be obtained. Preferably we take the composition afterbeing well ground and mixed, as usual, and ap ly it by means of a sieveor sifter to the sur ace of the matrix, so as to cover the face thereofcompletely, with'a layer a proximating one-third of the thickness of t efinlshed record. On this is placed the stock which is to form the bodypart of the record, and hydraulic pressure is then applied, as usual.

The operation may be most conveniently carried out by means of acircular sieve or sifter of well-known construction having the samediameter as the matrix. Placing such a sifter above the matrix andgiving a turn to the clearing device in the sifter causes the deposit onthe matrix of a layer of the composition of the required thickness. Thisoperation can be performed very expeditiously, and the results areentirely satisfactory. Preferably we use for this operation the sifteror sieve described in our application, Serial No. 289,936, filed January6, 1905.

The accompanying drawing illustrates conventionally the tablet resultingfrom our method, the relative thickness of the layer of powdered glazebeing slightly exaggerated.

Having now fully described our said invention, we claim- 1. The methodof forming a sound-record tablet by applying upon the surface of the dieor matrix a layer of plastic material in a dry and finely-divided state,and a layer of similar material in a plastic state, and uniting the twoby heat and pressure.

2. The method of forming a sound-record tablet by applying pressure totwo batches or layers of plastic material, one layer being in the formof a dry powder, the other in a plastic condition.

3. The method of forming a compressed sound-record by applying upon thesurface of a suitable matrix or die a layer of finelydivided materialcontaining a glaze, applying to said layer a batch of similar materialessentially free from glaze, and uniting the two layers by means of heatand pressure.

In testimony whereof we have signed this specification in the presenceof two subscribing witnesses.

WILLIAM HELM HOYT. WILLIAM JOSEPH GAVEN.

